Add to Safari
The Viewport Resizer is a plugin that can be added to the Safari browser that helps one test the responsiveness of their website. I use this tool during the web design process to make sure that my various breakpoints have been correctly configured.
Check Screen sizes
At the top of the screen is a black tool-bar and it displays icons that represent different browser sizes. You have one for high-definition TV you have a widescreen tablet in landscape and portrait has small tablet, Apple iPhone and also a mobile phone or a smartphone.
Easy to Use
What makes this Tool very easy to use is there is a slider located on the right-hand side of the webpage and you can quickly slide the slider in order to make sure that you got all the breakpoints covered.
This tool is also an excellent method of testing whether or not your website is responsive. It only takes two seconds to attach the widget to your browser and you can see what you’re viewers can see on your site.